1. Field of the Invention
This invention relates to a combined pulsator and drum type washing machine in which a pulsator type washing machine feature carrying out washing operation by virtue of rotation of a pulsator and a drum type washing machine feature carrying out washing operation by virtue of rotation of a drum are united such that they can be selectively utilized depending upon washing conditions.
2. Description of the Prior Art
Among various washing machines which have been used in the past, a pulsator type washing machine is of the type as shown in FIG. 1 of the accompanying drawings and comprises a single, combined washing and dehydration drum (will be hereinafter simply referred to as a "washing drum") 2 vertically disposed within a tub 1, a dehydrating shaft 3 coupled to the washing drum 2, a pulsator 4 rotatably disposed on the inner bottom of the drum 2, a pulsator shaft 5 fixed to the pulsator 4, a motor 6, and a clutch spring 7 disposed to selectively transmit power of the motor to the drum 2 and the pulsator 4 such that the drum and the pulsator are separately rotated selectively depending upon a given condition.
With this construction, during washing operation, when the power of the motor 6 is transmitted to the pulsator shaft 5 via the clutch spring 7, the pulsator 4 fixed to the pulsator shaft 5 for rotation therewith executes alternately forward and reverse rotations to carry out a washing function by tumbling over, rubbing or pressing articles to be washed, which are placed above the pulsator. During dehydrating operation, the driving force of the motor 6 is transmitted to the dehydrating shaft 3 by means of the clutch spring 7 such that the washing drum 2 coupled to the dehydrating shaft for rotation therewith is rotated to carry out the dehydration.
A drum type washing machine comprises, as shown in FIG. 2, a washing drum 2 horizontally disposed within a tub 1 and provided on its inner peripheral surface with a plurality of equally spaced lifters 11, a drum shaft 12 coupled to the washing drum and supported by a bearing contained in a bearing housing 13, a drum pulley 14 fixed to the rear end of the drum shaft 12, and a motor 15 secured to the underside of the tub 1 and having pulley 16 which is operatively connected to the drum pulley 14 by an endless belt 17 running around the pulleys, whereby the drum pulley may be rotated by the driving force of the motor.
With this construction, when the motor 15 is energized, the driving force of the motor is transmitted through the motor pulley 16, the belt 17, the drum pulley 14 and the drum shaft 12 to the washing drum 2 to rotate the drum. During the rotation of the drum, the articles to be washed are lifted and pressed by the lifters 11 formed on the inner periphery of the drum 2, and then dropped downwardly within the drum. Therefore, washing and dehydrating operations are carried out by an impact resulting from the dropping.
However, the pulsator type washing machine effecting washing operation by tumbling over, rubbing or pressing the articles to be washed is advantageous in that the washing may be accomplished in a short period of time, but has serious drawbacks in that the articles may be easily damaged and washing nonuniformity may appear. To the contrary, the drum type washing machine is advantageous in that since it effects washing operation by the impact generated when the articles to be washed are lifted and pressed by the lifters of the washing drum, and then dropped downwardly within the drum, although the drum is filled with large quantities of the articles, uniform washing may be achieved. However, the drum type machine has a drawback in that it takes relatively long time to carry out the washing operation.
Further, in case of the drum type machine, since the rotational axis of the drum crosses at a right angle with the direction of the gravity of the drum, vibration is produced due to an unbalance of the weight of the drum during the dehydration. In order to prevent such vibration, therefore, the washing machine must necessarily be provided with a counterbalance, resulting in increasing the weight. In addition, differently from the pulsator type, the user requires to inconveniently bend the body in order to put in and take out the articles at the front side of the machine.
There is accordingly a need to provide a combined washing machine having both of the pulsator type washing function and drum type washing function, and thus being capable to utilize only advantages of the pulsator and drum types, thereby to selectively carry out the washing and dehydrating modes depending upon the kinds of the articles to be washed and washing conditions.